I. First, determine the four key parameters (which dictate the machine model size)1) Pipe Diameter (D) × Wall Thickness (T) (Most important)Model designations are typically based on the maximum pipe diameter:DW38 / 50 / 63 / 75 / 89 / 114 / 130Rules of thumb (carbon steel, ambient temperature, R ≥ 2D):Φ10–30: Choose DW38…